1. Field of the Invention
The present invention relates to an electronic copier, and particularly to a cleaning unit of the copier for cleaning a charger for charging a photoconductor and a charge eliminator for eliminating charges from the photoconductor. More particularly, the present invention relates a cleaning unit that can maintain the quality of copier and reduce the useless consumption of toner.
2. Description of the Prior Art
In a standard electronic copier, a photoconductor is disposed around a photoconductor drum and uniformly charged with a charger. Charges at a non-image area of the photoconductor are eliminated by a charge eliminator. Then,the photoconductor is exposed by an exposure unit to form an electrostatic latent image corresponding to an original image on the photoconductor. The latent image is applied with toner to form a toner image, which is transferred onto a sheet of paper. The sheet is heated by a heater to fix the toner image on the sheet.
A charging wire of the charger for uniformly charging the photoconductor and the light emitting faces of a LED array (a charge eliminating lamp array) of the charge eliminator for removing charges from the non-image area of the photoconductor tend to stain with toner and paper dusts during the use. If they are stained, the photoconductor may not be charged uniformly to cause unevenness in an image to be formed, and the charge eliminator may insufficiently eliminate charges from the non-image area to uselessly increase the consumption of toner.
Conventionally, the electronic copier is periodically inspected by a serviceman, who disassembles the copier and cleans the charging wire of the charger and the LED array of the charge eliminator. However, such as cleaning work is not sufficient. To cope with this problem, there have been proposed various cleaning units for automatically cleaning the charger and charge eliminator. A typical cleaning unit comprises cleaning members for cleaning the charger and charge eliminator and a driving source of the cleaning members. The cleaning unit is operated during a warm-up period just after the energization of the copier.
Namely, the conventional cleaning unit cleans the charger and charge eliminator of the electronic copier only in the warm-up period just after the start of the copier. Since high-speed copiers have been developed to increase the frequency of use of the copiers, the copiers tend to be kept in an ON state for a long time. Therefore, a large number of copies are taken until the copiers are turned off, thus staining charging wires and the light emitting faces of LED arrays of the copiers. As a result, the quality of copies is deteriorated, and the useless consumption of toner is increased.